The present disclosure relates to magnetic resonance imaging (MRI).
MRI techniques have been widely applied in imaging applications in medical, biological and other fields. A typical MRI technique uses radio frequency (rf) magnetic field pulses to manipulate the magnetic spins in a subject and processes measured responses from the magnetic spins to produce an image of the subject or a portion of the subject. An MRI system may include hardware to generate various magnetic fields for imaging, including a static magnetic field (B0) along a z-direction to polarize a portion of the magnetic spins, gradient fields along mutually orthogonal x, y, or z directions, and an rf magnetic field to manipulate the spins. Functional MRI techniques measure variations in the blood flow in the brain to indicate the distribution of the brain activities.